Following severe injury, not just the skin but also the subcutis may be destroyed. Consequently, the developing scar can become adherent to underlying structures. Reconstruction of the subcutis can be achieved by autologous fat grafting. Our aim was to evaluate the long-term scar outcome after single-treatment autologous fat grafting using a comprehensive scar evaluation protocol. Scar assessment was performed preoperatively in 40 patients. A 12-month follow-up assessment was performed in 36 patients, using the Cutometer, the Patient and Observer Scar Assessment Scale, and DSM II ColorMeter. The Cutometer parameters elasticity and maximal extension improved with 28 and 22% (both p < 0.001), respectively. Nearly all scores of the scar assessment scale decreased significantly, which corresponds to improved scar quality. In addition, the mean melanin score was ameliorated over time. Thus, we demonstrated the sustainable effectiveness of single-treatment autologous fat grafting in adherent scars, indicated by improved pliability, and overall scar quality.